Object perception - VS Flashcards Preview

Pathology > Object perception - VS > Flashcards

Flashcards in Object perception - VS Deck (70)
Loading flashcards...
1

which area in the brain of a monkey is all purpose simple form & all object processors found

V4/IOT (inferior occipital temporal cortex)

2

which area in the human brain is all purpose simple form & all object processors found

LOC (lateral occipital cortex) area

3

in both monkey and human brain, where are more specialised object processors found for recognising faces and buildings

IT (inferior temporal), fusiform gyrus, several areas

4

in both monkey and human brain, where are more specialised object processors found for spatial scenes/places and navigating through them

IT (inferior temporal)/ParaHippocampal gyrus

5

which serial processing is used to rebuild the object image

from: V1/V2 - V4 - IOT - IT (where real objects are encoded)

6

what are the form processing cells in area v1 & v2 and what do they respond to

orientation selective
respond to lines & edges

7

where are the form processing cells located in area v1 & v2

in interblob zones of layers 2-4A & 5-6 (in v1)

8

what are the form processing RF sizes in area v1/v2

relatively small 0.1 (fovea) - 2 (bit eccentric) degrees, depending on visual eccentricity

9

what are the form processing RFs organisation like in area v1/v2

- simple ~15%: linear discrete ON & OFF sub-regions
- complex ~75%: non-linear, overlapping ON/OFF regions
- hypercomplex ~10%: end-stopped inhibition, so also size selective and well as orientation selective

10

what do RF organisations of form processing cells in area V1/V2 interested in

only like lines/edges of a particular orientation and hate ones that are at 90 degrees

11

how many % off cells in area v1 are orientation selective and what do they respond best to

75%
respond best to contours (lines, edges) over a narrow range of possible orientations but not to other orientations of the same stimulus

12

what are the orientation selectivity cells in area v1 responses independent of, and except which population

independent of the size of the oriented stimulus
except among a small population 5-10% of 'end-stopped' or hyper-complex cells

13

what two sub-divisions is monkey area V4 believed to contain

1. one primarily concerned with colour vision
2. other mainly concerned with form vision

14

what are the RFs of the sub division of monkey area v4 concerned with form vision size, compared to area v1 at equivalent visual field locations

2-5x larger

15

what component is 2-5x compared to another component in a monkey brain

the RFs of the sub division of monkey area v4 concerned with form vision size, compared to area v1 at equivalent visual field locations

16

what does monkey area v4 sub-division concerned with form vision, contain none of, and only of which RF organisations

no simple cells (beyond v1 & v2)
all RF organisations are complex or many are hyper-complex (end-stopped)

17

in monkey area v4 sub-division concerned with form vision what are ~50% of cells

orientation selective
but they ALL prefer stimuli of a particular size (width verses length)

18

what do the ~50% of orientation selective cells in monkey area v4 sub-division concerned with form vision all prefer

stimuli of a particular size (width verses length)

19

how is RF sizes in functional specialisation for object & motion perception areas V4, IOT & IT compared to V1 cortex

increased RF sizes at all eccentricities (neurons analysing a larger region of space)

20

how is orientation selectivity in functional specialisation for object & motion perception areas V4, IOT & IT compared to V1 cortex

reduced orientation selectivity and absent in IT
replaced by size-shape or object category-selectivity

21

what are orientation selectivity in functional specialisation for object & motion perception areas in V4, IOT & IT replaced by

size-shape or object category-selectivity

22

how are the specific form attribute in functional specialisation for object & motion perception areas V4, IOT & IT compared to V1 cortex

columnar organisation for that specific form attribute that the area is responsible for and specialised to encode

23

how are the representation of central vision where perception mainly occurs in functional specialisation for object & motion perception areas V4, IOT & IT compared to V1 cortex

biased representation of central vision, where object perception mainly occurs, in object processing pathway areas only concerned with central vision, central 20 degrees where we identify & recognise objects and peripheral VF representations disappear the higher up the pathway you go

24

how is the retinotopic order in functional specialisation for object & motion perception areas V4, IOT & IT compared to V1 cortex

loss of retinotopic order

25

what does RF sizes increase with for V1, V2, V4 & IOT & IT cells

eccentricity, by a linear correlation

26

what does the increase in size of RF with eccentricity increase gradually from

V1 to V2 to V4 & becomes really large in IT & IOT cortex

27

what is the increase in RF size in V1 V2 V4 & IT & IOT mirrored by

increase in RF complexity

28

what are V1 and V2 RFs mainly concerned with

fragments of objects (lines and edges)

29

what are V4 and IT & IOT RFs mainly concerned with

simple geometric shapes & real objects and complex shapes (components of objects)

30

what are most of the ~50% of v4 cells which are orientation selective

end stop tuned
to the size of the stimulus (like hyper column v1 cells)
where e.g. in a box RF, a line placed inside it must be confined to the RF size, if extended the RF will shut off